Field of the Invention
The present invention relates to a meat grinder, and more particularly to a meat grinder that can be operated smoothly.
Description of Related Art
With reference to FIGS. 4 and 5, a conventional meat grinder comprises a motor assembly 80 and a grinding assembly 90. The motor assembly 80 comprises a rectangular casing and a motor mounted in the casing. The motor has a hollow output axle 81. The grinding assembly 90 is connected to a front side of the motor assembly 80 and comprises a grinding tube 91, a threaded rod 92, a blade 93, an extrusion panel 94, and a limiting collar 95. The grinding tube 91 is L-shaped, and the threaded rod 92 is rotatably mounted in the grinding tube 91. The threaded rod 92 has an annular abutting flange 921 formed around the threaded rod 92 at a position adjacent to a rear end of the threaded rod 92 and a connecting axle 922 formed on the rear end of the threaded rod 92. The connecting axle 922 is inserted into and connected with the output axle 81. The blade 93 is mounted on a front end of the threaded rod 92. The extrusion panel 94 is mounted on a front end of the grinding tube 91 and is spaced from the blade 93. The limiting collar 95 is mounted around the connecting axle 922 and abuts the abutting flange 921 and the front side of the motor assembly 80. A gap is formed between an end surface of the connecting axle 922 and an inner bottom surface of the output axle 81, such that the limiting collar 95 is kept abutting the abutting flange 921 and the blade 93 is kept being spaced from the extrusion panel 94. Accordingly, the threaded rod 92 is kept from being interfered with an inner surface of the grinding tube 91, and the rotation of the threaded rod 92 is smooth.
However, when the limiting collar 95 is a bearing, lubricant oil in the bearing may leak out from the bearing and pollute the ground meat in the grinding tube 91 by the threaded rod 92. In addition, the rotation of the bearing with leaking lubricant oil is not smooth and even jammed. Furthermore, the temperature of the bearing will increase after a time of operation, the high temperature of the bearing will cause bad influence to the quality of the meat.
When the limiting collar 95 is made of resilient plastic steel, the plastic steel limiting collar 95 is not rotated with the threaded rod 92 synchronously. A friction is generated between the limiting collar 95 and the threaded rod 92, and the powders dropped from the limiting collar 92 will also pollute the ground meat. In addition, the temperature of the limiting collar 95 will increase due to the friction, the high temperature of the limiting collar 95 will also cause bad influence to the quality of the meat.
When the limiting collar 95 is made of copper, the copper limiting collar 95 has a higher stiffness than the plastic steel limiting collar. The copper limiting collar 95 does not easily produce powders during the rotation of the copper limiting collar 95, but the rotation of the threaded rod 92 is not smooth because of the high stiffness of the copper limiting collar 95. In addition, the temperature of the limiting collar 95 and the threaded rod 92 will increase due to the friction, the high temperature of the limiting collar 95 and the threaded rod 92 will also cause bad influence to the quality of the meat.
To overcome the shortcomings, the present invention tends to provide a meat grinder to mitigate or obviate the aforementioned problems.